1. Field of the Invention
The invention relates to a method as well as a device for electrostatic charging of the two outer sides of at least one material web with charges of opposite polarity, prior to the further processing of the at least one material web wherein the web is guided through the nip of a pair of rollers that are parallel to one another and have a small distance between them.
2. Description of the Prior Art
A method of this kind and a device for electrostatic charging is known (DE 31 17 419 A1). In this document, a plurality of material webs are brought together to form a hank and only the two outer sides are charged by means of a device designed as a corona-charging electrode for electrostatic charging downstream from the first pair of rollers by means of a high voltage source of 30 kV.
The disadvantage of this known device is a charging of the two outer sides of the material webs that is not highly directed in space. Thus, a large number of charged particles migrate throughout the area where charging is taking place. This results in poor charging efficiency. In addition, there is the danger that under unfavorable environmental conditions, the corona charging electrodes will become contaminated and consequently fall to operate. The cleaning expense can be very high.